Modulator



Mar. 27, 1923.

1,449,871. J. B. PRATT. I

MODULATOR.

HLED IAN-12,1922.

Fig.1.

Inventor:

John Pratt, b5 His Attorney o i e ell whom it may concern.

Patented Mar. 27, 1823.

UNITED STATES,

JOHN B. rna r'r, E

A MODULATOR,

Baits-known that L'JOHN B; PRATT, a citizen of the United States, residing at i "Schenectady in' the county of Schenectady,

State of New York, haveinvented certain new and useful Improvements in Modulators, of which the following is a specification. v

My present invention relates to modu lators of high frequency current, and more particularly to modulators of the type commonly known as magnetic amplifiersI Devices of this general type as used in the past, described for example in U. S. patent to Alexanderson 1,206,643, have ordinarily been. constructed with the closed magnetic core made up of thin laminations.

They have been constructed either by first I assembling the lamiriations of the core and then winding the coils on this core by threading the conductor through the openinserted withinthe coils.

The object of my invention is to provide an improved method of constructing,

the magnetic core of .such a device which will be simpler than previous methods and; result in an improved product. In carrying my invention into effect I first windfthe coils which are to surround the closed mag -netic core and then form the core by thread ing a thin ribbon of magnetic material thro h the coils making enoughturns in this ribbon to provide the desired cross sec-1 tional area of the core. a I i The novelfeatures which "I believe to be characteristic of my invention'are-set forth with particularity in the appended'claims,

myinvention itself, however, both as to ings broken away.

its organization and method "of operation will best be understood by referenceto the following description taken in connection with the. accompanying drawing in which Fig. 1 shows diagrammatically the application of my invention to a radio telephone transmitting system, and Fig. .2 is aview of the modulator-with; a portion of the wind- 1 and 2 surrounding the two leg's"3 and 4,

magnetic core.

Application m January 12,1922. Serial No. 528,845.

of a closed magnetic core made up of thin laminations. In constructing this modulator the coils 1 and 2 are first wound upon the s ools 5 and 6, and then placed side by side.

he core is then formed by threading a thin ribbon of the desired magnetic material continuously through the spools 5 and 6,

enough turns of this ribbon being made to furnish the, desired cross-section of the This ribbon may be made of electrolytic iron ,or mild steel," rolled down to a thickness of about 1 mil and eninsulation between the'turns of the ribbon.

Surrounding. the coils 1 and 2 is a winding made up of portions 7 and 8 wound in opposite directions. The winding 7, 8 is connected in series with a radiating antenna 9, which is supplied with high frequency current froma' source 10 through the usual coupling transformer. 11. The source 10 may be ,of any'form desired; a high frequency alternator, an arc generator, or a va-cuumtube generatohwModulation of the antenna current is effected by supplying a telephone current by means of a transmitter 12, and a local battery '13 to the windings l and 2.

What I claim as new and desire to secure by-L'ettersPatent of the United States,

vIQThe method of constructing a magnetic .device for modulating .high frequency currents which consists in Winding two similar coils, placing the'two coils side by side, and forming a continuous magneticcore for the magneticfield which may be produced by currents flowing in said 'coilsf'by threading a thin ribbon of magneticmaterial through said oils. q

2.- The method of constructing a -magnetic device for modulating high" frequency currents which consists in, winding two .PATENT' OFFICE.

scnENEc'rAnY, NEw'Yonx, AssIGNoR To GENERAL ELECTRIC COMPANY, A CORPORATION 01- NEW YORK.

'ameled, the enamel furnishing the desired similar coils, placing thetwocoils side by side, and forming a continuous magnetic core for the magnetic field which may be produced by currents flowing in. said coils by threading a thin ribbon. of magnetic material through said coils, and winding a coil around, both-of said first mentioned coils either before or after the magnetic core is formed. 1

,3, The combination in a modulator of-a pair-of similar coils side by side, a core for the magnetic field which may be produced formed of a continuous thin ribbon. of magnetic material threaded throughsaid coils, a winding surrounding both of said coils, and means for supplying high frequency currents to said surrounding winding.

5. The combination in a signaling system of a pair of similar coils side by side, means for supplying audio frequency signaling currents to said coils, a core for the magnetic field produced by'saidsignaling currents formed of a continuous thin ribbonof magnetic material threaded through said coils, a Winding surrounding both of said coils, a transmitting circuit in Which the surrounding winding is included, and means for supplying high frequency currents to said transmitting circuit.

In witness whereof, I have hereunto set my hand this 6th dayof January, 1922..

JOHN B. PRATT. 

